/* -*- linux-c -*- ------------------------------------------------------- *
 *
 *   Copyright (C) 1991, 1992 Linus Torvalds
 *   Copyright 2007 rPath, Inc. - All Rights Reserved
 *
 *   This file is part of the Linux kernel, and is made available under
 *   the terms of the GNU General Public License version 2.
 *
 * ----------------------------------------------------------------------- */

/*
 * Oh, it's a waste of space, but oh-so-yummy for debugging.  This
 * version of printf() does not include 64-bit support.  "Live with
 * it."
 *
 */


#include "common/code32gcc.h"
#include "x86/kernel/printf.h"
#include "x86/kernel/string.h"
#include "x86/kernel/screen.h"

static int skip_atoi(const char **s) {
  int i = 0;

  while (isdigit(**s))
    i = i * 10 + *((*s)++) - '0';
  return i;
}

#define ZEROPAD	1		/* pad with zero */
#define SIGN	2		/* unsigned/signed long */
#define PLUS	4		/* show plus */
#define SPACE	8		/* space if plus */
#define LEFT	16		/* left justified */
#define SMALL	32		/* Must be 32 == 0x20 */
#define SPECIAL	64		/* 0x */

#define do_div(n,base) ({                               \
      int __res;                                        \
      __res = ((unsigned long) n) % (unsigned) base;    \
      n = ((unsigned long) n) / (unsigned) base;        \
      __res; })

static char *number(char *str, long num, int base, int size, int precision,
		    int type)
{
  /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
  static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */

  char tmp[66];
  char c, sign, locase;
  int i;

  /* locase = 0 or 0x20. ORing digits or letters with 'locase'
   * produces same digits or (maybe lowercased) letters */
  locase = (type & SMALL);
  if (type & LEFT)
    type &= ~ZEROPAD;
  if (base < 2 || base > 36) {
    return NULL;
  }
  c = (type & ZEROPAD) ? '0' : ' ';
  sign = 0;
  if (type & SIGN) {
    if (num < 0) {
      sign = '-';
      num = -num;
      size--;
    } else if (type & PLUS) {
      sign = '+';
      size--;
    } else if (type & SPACE) {
      sign = ' ';
      size--;
    }
  }
  if (type & SPECIAL) {
    if (base == 16)
      size -= 2;
    else if (base == 8)
      size--;
  }
  i = 0;
  if (num == 0)
    tmp[i++] = '0';
  else
    while (num != 0)
      tmp[i++] = (digits[do_div(num, base)] | locase);
  if (i > precision)
    precision = i;
  size -= precision;
  if (!(type & (ZEROPAD + LEFT)))
    while (size-- > 0)
      *str++ = ' ';
  if (sign)
    *str++ = sign;
  if (type & SPECIAL) {
    if (base == 8)
      *str++ = '0';
    else if (base == 16) {
      *str++ = '0';
      *str++ = ('X' | locase);
    }
  }
  if (!(type & LEFT))
    while (size-- > 0)
      *str++ = c;
  while (i < precision--)
    *str++ = '0';
  while (i-- > 0)
    *str++ = tmp[i];
  while (size-- > 0)
    *str++ = ' ';
  return str;
}

int vsprintf(char *buf, const char *fmt, va_list args) {
  int len;
  unsigned long num;
  int i, base;
  char *str;
  const char *s;

  int flags;		/* flags to number() */

  int field_width;	/* width of output field */
  int precision;		/* min. # of digits for integers; max
				   number of chars for from string */
  int qualifier;		/* 'h', 'l', or 'L' for integer fields */

  for (str = buf; *fmt; ++fmt) {
    if (*fmt != '%') {
      *str++ = *fmt;
      continue;
    }

    /* process flags */
    flags = 0;
 repeat:
    ++fmt;		/* this also skips first '%' */
    switch (*fmt) {
      case '-':
        flags |= LEFT;
        goto repeat;
      case '+':
        flags |= PLUS;
        goto repeat;
      case ' ':
        flags |= SPACE;
        goto repeat;
      case '#':
        flags |= SPECIAL;
        goto repeat;
      case '0':
        flags |= ZEROPAD;
        goto repeat;
    }

    /* get field width */
    field_width = -1;
    if (isdigit(*fmt))
      field_width = skip_atoi(&fmt);
    else if (*fmt == '*') {
      ++fmt;
      /* it's the next argument */
      field_width = va_arg(args, int);
      if (field_width < 0) {
        field_width = -field_width;
        flags |= LEFT;
      }
    }

    /* get the precision */
    precision = -1;
    if (*fmt == '.') {
      ++fmt;
      if (isdigit(*fmt))
        precision = skip_atoi(&fmt);
      else if (*fmt == '*') {
        ++fmt;
        /* it's the next argument */
        precision = va_arg(args, int);
      }
      if (precision < 0)
        precision = 0;
    }

    /* get the conversion qualifier */
    qualifier = -1;
    if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L') {
      qualifier = *fmt;
      ++fmt;
    }

    /* default base */
    base = 10;

    switch (*fmt) {
      case 'c':
        if (!(flags & LEFT))
          while (--field_width > 0)
            *str++ = ' ';
        *str++ = (unsigned char)va_arg(args, int);
        while (--field_width > 0)
          *str++ = ' ';
        continue;

      case 's':
        s = va_arg(args, char *);
        len = strnlen(s, precision);

        if (!(flags & LEFT))
          while (len < field_width--)
            *str++ = ' ';
        for (i = 0; i < len; ++i)
          *str++ = *s++;
        while (len < field_width--)
          *str++ = ' ';
        continue;

      case 'p':
        if (field_width == -1) {
          field_width = 2 * sizeof(void *);
          flags |= ZEROPAD;
        }
        str = number(str,
                     (unsigned long)va_arg(args, void *), 16,
                     field_width, precision, flags);
        continue;

      case 'n':
        if (qualifier == 'l') {
          long *ip = va_arg(args, long *);
          *ip = (str - buf);
        } else {
          int *ip = va_arg(args, int *);
          *ip = (str - buf);
        }
        continue;

      case '%':
        *str++ = '%';
        continue;

        /* integer number formats - set up the flags and "break" */
      case 'o':
        base = 8;
        break;

      case 'x':
        flags |= SMALL;
      case 'X':
        base = 16;
        break;

      case 'd':
      case 'i':
        flags |= SIGN;
      case 'u':
        break;

      default:
        *str++ = '%';
        if (*fmt)
          *str++ = *fmt;
        else
          --fmt;
        continue;
    }
    if (qualifier == 'l')
      num = va_arg(args, unsigned long);
    else if (qualifier == 'h') {
      num = (unsigned short)va_arg(args, int);
      if (flags & SIGN)
        num = (short)num;
    } else if (flags & SIGN)
      num = va_arg(args, int);
    else
      num = va_arg(args, unsigned int);
    str = number(str, num, base, field_width, precision, flags);
  }
  *str = '\0';
  return str - buf;
}

int sprintf(char *buf, const char *fmt, ...) {
  va_list args;
  int i;

  va_start(args, fmt);
  i = vsprintf(buf, fmt, args);
  va_end(args);
  return i;
}

int printf(const char *fmt, ...) {
  char printf_buf[1024];
  va_list args;
  int printed;

  va_start(args, fmt);
  printed = vsprintf(printf_buf, fmt, args);
  va_end(args);

  puts(printf_buf);

  return printed;
}
